火灾
huǒzāi · HSK 5
fire
🔥 火 (fire) + 灾 (disaster) = fire-disaster, i.e. a conflagration
火灾 is a compound: 火 means fire, 灾 means disaster or calamity. The 灾 character itself shows 火 (fire) under 宀 (roof) — a house-fire built right into the etymology.
火 — pictograph of flames rising
火 is a pictograph showing flames rising upward from a fire, with the central stroke as the main blaze and the side strokes as sparks. The ancient oracle bone form looked even more clearly like a burning flame. It still means 'fire' today and serves as a common radical in characters related to heat, burning, or cooking.
灾 — roof 宀 + fire 火
灾 is an associative compound showing fire (火) under a roof (宀), depicting a house on fire — the original meaning of 'disaster' or 'calamity'. An older variant 災 added 巛 (flooding water) above 火, combining flood and fire as twin disasters. The modern simplified form keeps just the house-fire image.